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Studies on Sulphate reducing bacteria from Southeast coast of India
G. Abirami, R. Anburaj & K. Kathiresan
CAS in Marine Biology, Annamalai University, Parangipettai - 608 502, Tamil Nadu, India. E-mail:
[email protected] / [email protected]
Abstract
A striking feature in mangroves ecosystem is a large anaerobic substratum enriched with
anaerobic microorganisms predominantly sulphate reducing bacteria. However, research
studies on the role of sulphate reducing bacteria in the functioning of mangrove ecosystem
are only scanty. Therefore the present work was undertaken to study occurrence and
distribution of sulphate reducing bacteria in luxuriant or degrading mangroves at 10 different
sediment depths for four seasons. Sediment soil samples were collected from Pichavaram
mangrove forest situated along the southeast coast of India and inoculated in specific
Postgate’s B liquid medium, prepared completely in anaerobic condition. The sulphate
reducing bacteria were enumerated by serial dilution method, after incubation up to 2 to 3
weeks. The results revealed that the sulphate reducing bacterial counts started increasing
from 30 cm depth; the counts were higher during post monsoon and summer and lower in
pre-monsoon and monsoon. The bacterial counts were higher in luxuriant mangroves than
that in degrading stands. The role of sulphate reducing bacteria in mangrove functioning is
discussed. The presence of sulphides is a characteristic feature of mangrove sediments and it
influences the distribution of mangroves. Tolerance to sulphides varies with mangrove
species.
Keywords
sulphate reducing bacteria, ecosystem function, seasonal influence
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